# Sub Applications - Mounts { #sub-applications-mounts }

If you need to have two independent FastAPI applications, with their own independent OpenAPI and their own docs UIs, you can have a main app and "mount" one (or more) sub-application(s).

## Mounting a **FastAPI** application { #mounting-a-fastapi-application }

Follow your cloud provider's guides to deploy FastAPI apps with them. 🤓

## Deploy your own server { #deploy-your-own-server }

All the **logic** about how to register the URLs for webhooks and the code to actually send those requests is up to you. You write it however you want to in **your own code**.

## Documenting webhooks with **FastAPI** and OpenAPI { #documenting-webhooks-with-fastapi-and-openapi }

///

Before OpenAPI 3.1.0, OpenAPI used an older and modified version of **JSON Schema**.

JSON Schema didn't have `examples`, so OpenAPI added its own `example` field to its own modified version.

OpenAPI also added `example` and `examples` fields to other parts of the specification:

This directory contains JLine native libraries extracted from JLine JAR.

You can add your own build for platforms not natively supported by JLine.
See here [1] on how to compile for your platform and here [2] how libraries
follow JLine's directory and filename conventions.

[1] https://github.com/jline/jline3/tree/master/native

tags_metadata = [
    {
        "name": "users",
        "description": "Operations with users. The **login** logic is also here.",
    },
    {
        "name": "items",
        "description": "Manage items. So _fancy_ they have their own docs.",
        "externalDocs": {
            "description": "Items external docs",
            "url": "https://fastapi.tiangolo.com/",
        },
    },
]

app = FastAPI(openapi_tags=tags_metadata)

          <description>
            Toolchain identification information, which will be matched against project requirements.
            &lt;p>Actual content structure is completely open: each toolchain type will define its own format and
            semantics.
            &lt;p>This is generally a properties format: {@code &lt;name&gt;value&lt;/name&gt;} with predefined
            properties names.
          </description>
        </field>

class EndpointContext(TypedDict, total=False):
    function: str
    path: str
    file: str
    line: int


class HTTPException(StarletteHTTPException):
    """
    An HTTP exception you can raise in your own code to show errors to the client.

    This is for client errors, invalid authentication, invalid data, etc. Not for server
    errors in your code.

    Read more about it in the

            // Verify that child1 has its own repository
            boolean child1HasOwnRepo = child1Project.getRemoteArtifactRepositories().stream()
                    .anyMatch(repo -> "child1-repo".equals(repo.getId()));
            assertTrue(child1HasOwnRepo, "Child1 should have its own repository");

            // Verify that child2 has its own repository

from contextlib import AsyncExitStack

from starlette.types import ASGIApp, Receive, Scope, Send


# Used mainly to close files after the request is done, dependencies are closed
# in their own AsyncExitStack
class AsyncExitStackMiddleware:
    def __init__(
        self, app: ASGIApp, context_name: str = "fastapi_middleware_astack"
    ) -> None:
        self.app = app
        self.context_name = context_name